Electric meter.



No. 698,64L Patented Apr. 29, !902.

T. DUNCAN.

ELECTRIC METER.

(Application filed Aug. 1, 1898.] (No Model.) 2 Sheets-Sheet I.

Fig. 1.

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N0. 698,64L Patented Apr. 29, I902.

T. DUNCAN.

ELECTRIC METER. (Appliation filed Aik 1, 189B.) (No Model.) 2 Sheafs-Sheet 2.

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UNITED STATES; PATENT OFFICE.

THOMAS DUNCAN, OF FORT WAYNE, INDIANA, ASSIGNOR TO THE SIEMENS (K6 HALSKE ELECTRIC COMPANY OF AMERICA, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

ELECTRIC METER.

SPECIFICATION forming part of Letters Patent No. 698,641, dated April 29, 1902. Application filed August 1, 1898. Serial No. 687,3 90. (No model.)

To all whom it y Jon/667%! the reason that it does not require an addi- Be it known that I, THOMAS DUNCAN, a cititional amount of energy in the shunt fieldzen of the United States, residing at Fort coil as aprimary to induce the necessary cur- Wayne, in the county of Allen, in the State rents by induction in the closed secondary, of Indiana, have invented certain new and and at the same time has all the advantages 55 useful Improvements in Electric Meters; and of receiving a subsidiary shunt-current to I do hereby declare that the following is a augment the lag of the magnetism through full, clear, and exact description of the inventhe shunt field-coil without the use of a transtion, which will enable others skilled in the former or without being connected directly to art to which it appertains to make and use the the supply-mains and having a resistance in 60 same, reference being had to the accompanyseries therewith which incurs extra losses. ing drawings, which form part of this specifi- In the accompanying drawings, which form cation. part of this specification, similar reference- My invention relates to improvements in numerals indicate like parts.

the method of and means for regulating and Figure 1 isa front elevation of my improve- 65 adjusting the phase of the magnetism which ment with the volt or shunt coils in cross-secrepresents the electromotive force in induction. Fig. 2 shows diagrammatically the relation motor-wattmeters, and particularly to tive position of the energizing-coils in combi the class or type of meters in which the said nation with a cylindrical armature. Figs. 3,

2o magnetism is a resultant of two magnetizing 4, and 5 are also modifications of my inven- 7o coils or fields in cooperative relation. tion shown diagrammatically and employing One object of my invention is to provide a cylindrical type of armature which is dean efficient and simple means for adjusting scribed in detail hereinafter. the magnetism of the volt coil or field into The principal elements employed in my in- 2 5 quadrature with the electromotive force or vention are a series coil or coils, a shunt or 75 for causing it to lag ninety degrees behind volt coil, an auxiliary shunt or volt coil, magthe said electromotive force, whereby the menets arranged in cooperative relation with the ter is enabled to measure inductive loads. said armature, an impedance-coil, a register- Another object of my present improvement ing mechanism, and means for energizing the is to enable the meter to measure accurately said auxiliary shunt or volt coil in multiple So on varying rates of periodicity, as found or shunt to a portion of the turns or convoluamong the many systems at present in use. tions of the impedance-coil.

Another object of my improvement is to It is now well understood by those skilled provide a simple and cheap means of emin the art that an induction motor meter 3 5 ployinga combined autotransformer and imadapted to measure the energy on inductive 85 pedance-coil which lags the shunt-current loads, such as motors, must be. so organized through the volt or pressure field-coil to an that the magnetism,which represents the elec amount less than ninety degrees, to also suptromotive force in volts, must be ninety deply part of its current to energize a phasegrees from or in quadrature with said elec- 0 lagging coil used in inductive relation with tromotive force and must also be ninety de- 9:: the volt or pressure field-coil, and then comgrees from the magnetism of the series or bining the magnetic fields set up by these two ampere coil or field when the load in the workphases of the same current into a resultant circuit is non-inductive and its current is in magnetic field having a greater lag than the phase or step with the line-pressure. When current traversing the-impedance-coil. Ialso this condition is secured, the torque exerted 5 find that this means of obtaining a magnetic will be proportional to the real or true watts field in quadrature with the impressed elecand the sine of the angle between the magnettromotive force is more efiicient than that in ism of the volt and ampere coils, respectively. whicha closed secondary alone is used in co- Referring now particularly to Fig. 1, the

operation with the shunt or volt field-coil, for generator 1 supplies energy to the translat- 10o ing devices by means of the circuit-leads 2 and 3 and energizes the field or ampere coils 4. Upon a suitable step or bearing is erected the upright revoluble spindle 18, having its upper end in mesh with and adapted to actuate a proper registering-train 19 in a well-understood manner. Atasuitable point on said spindle is rigidly fixed an aluminium disk armature 16, arranged in inductive rela tive relation to the field or ampere coils 4. Adjacent to the upper face of the said disk armature is arranged a shunt or volt coil 6, which is wound with fine wire and is connected in series with a suitable impedancecoil 8, the said coil 6 and the said impedance coil both being supplied with current in shunt from the mains by means of wires 11, 12, and 13. Within the said volt-coil 6 is arranged an auxiliary coil 7, in coaxial and cooperative relation therewith. The function of the impedance-coil is to assist in causing the current and magnetism of the said coil 6 to lag as nearly as is possible to ninety degrees behind the pressure of the generator 1; but it being understood that the lag of the said im pedancecoil must necessarily be somewhat less than ninety degrees I employ the auxiliary coil 7 in cooperative relation with the volt-coil 6 and energize the former with current shunted from a portion of the impedance-coil 8 to obtain the desired quadrature. The terminals of the auxiliary coil 7 are shunted around a portion of theturns or convolutions of the impedance-coil by means of the wires 14 and 15 and a suitable switch 9 and also includes in cooperation therewith a variable resistance 10. If-the current and magnetism of the coil 6 lag, say, eighty-five degrees behind the line-pressure, the switch 9 and resistance 10 are adjusted until the magnetism of the coils 6 and 7 form a resultant magnetic field that is exactly ninety degrees or in quadrature. An angle greater than ninety degrees may be easily obtained, if desired. The disk armature 16 isactuated by the shifting magnetism resulting from a combination of the magnetic effects of the said volt and ampere field coils in a well-understood manner. To make the speed of the meter proportional to the energy, I employ the usual permanent magnets 17, which. are adapted to embrace the disk 16 between their poles.

Fig. Zshows a cylindrical type of armature and also shows the resistance 10 shunted around the auxiliary coil 7 at the ends of the wires 14 and 15. This arrangement of the resistance has the advantage of altering or varying the magnitude of the current through both of the coils 6 and 7, thereby quickly and-effectively altering the angulardisplacement of their resultant magnetic field to or from the impressed electromotive force. If the currents through these coils 6 and 7 are adjusted so that their resultant magnetism is exactly ninety degrees behind the pressure and the resistance 10 is then reduced, more current will pass through the coil 6 and less through the coil 7, thereby increasing the magnitude of the magnetism of the coil .6 and reducing that of the coil 7, resulting in a change or dis placement of the phase of the resultant magnetism back toward the impressed eleotromotive force. If the resistance 10 is increased, then the result will be the opposite of the foregoing, in that the resultant magnetism of the coils 6 and 7 will be made to lag more than ninety degrees, since the magnitude of the flux of the-coil 6 is decreased and that of the lagging coil increased.

Fig. 3 exhibits a form of impedance-coil, with a detached portion 22, that is separated from the coil proper by the wooden blocks 21. The detachable portion 22 has wound thereon a number of turns which are in series with the windings upon the core 8 and are, in fact, a part of the whole impedance-coil. The terminals 14 and 15 of the lagging coil 7 are con nected to the terminals of the windings upon said detachable portion 22. In employing this construction it is found to be very convenient, for the reason that for different windings of the coil 7 the pressure supplying current to energize said coil can be quickly adjusted by varyingthe number of turns upon the detachable portion when the meter is being tested and also adjustingitfor different frequencies.

Fig. 4 shows the detachable portion 22 wound in such a manner that the several convolutions are connected to suitable contactpoints and a switch 9, whereby any or all of them may be cut into circuit to obtain the requisite pressure to supply the proper amount of current to the lagging -coil 7. WVith this arrangement I find that the variable resistance 10 may be dispensed with, provided that the drop or pressure over each con-. volution on the detachable part 22 is not too great. This, however, can easily be averted in designing the impedance-coil when it is desired to eliminate the resistance 10. For accurate work, however, combined with quickness of testing, the arrangement shown in Fig. 5 is preferable. This figure shows the variable resistance 10 in combination with the variable contact-switch 9 for switching in any desired number of turns wound upon the detachable portion 22 of the impedance-coil core. This arrangement also provides a ready means for adjusting the meter for different pressures without necessitating a change in the turns wound upon the portion 22suc h, for example, as a case in which a one-hundred-volt meter is to be calibra-ted for, say, two hundred volts, the switch may be moved to cut out one or more of the turns wound upon the portion 22 and the wooden blocks 21 made smaller, so as to allow the said portion 22 to come nearer to the portion 8, thereby increasing the self-induction of the impedance-coil and preventing the flow of too much current through the shunt-circuit when the pressure is doubled.

I am aware that the use of two coils supplied by currents differing in phase to produce a lagging magnetic field-that is, in quadrarived from a combined autotransformer and impedance-core for the purpose set forth without the useofa closed secondary, paral lel transformer, or other shunt-circuit receiving current from the supply-mains, provid ing therebya meter to comply with the present demands of the central-station manager, which must embody simplicity-with the highest efficiency.

It will be observed that the difierent embodiments of the invention'illustrated, for example, in Figs. 1 and 2 each possess an impedance-winding and a phase-modifyingportion included between turns of the impedancewinding. In Fig. 2 this phase-modifying'portion is a resistance 10, while in Fig. l the phase-modifying portion is a metallically-continuous part, or, in other words, the secondary of the autotransformer.

Having thus briefly described the construc- 2. In a system of alternating-current distribution,tl1e combination with an alternating current generator of current and pressure field-windings of a meter receiving current from said generator, the latter winding being divided into two coils, an autotransformer having its winding included conductively in circuit with one of the pressure-coils and a portion of its winding included in a closed local circuit, the remaining pressure-coil being also included incircuit with the latter portion of the autotransformer, the coils of the pressure-winding being inductively related, and a measuring device subjected to the action of the field-windings,substantially as described.

3. In a system oftransrn-ission, the combination with an alternatingcurrent generator of current and pressurefield-windings of a meter receiving current from said generator the latter winding being divided into two in ductivelyrelated coils, an autotransformer having its winding included conductively in circuit with one of the pressure-coils and a portion of its winding included conductively in circuit with the remaining pressure-coil,

and an armature in inductive relation to the said pressure-coils,substantiallyas described,

4. In a system of alternating current distribution, the combination with an alternatingcurrent generator of current and pressure field-windings of a meter receiving current from said generator, the latter winding being divided into two coils, an autotransformer having its winding included conductively in circuit with ofie of the pressure-coils and a portion of its winding included conductively in circuit with the remaining pressure-coil, a

measuring device subjected to the action of the field-windings, and a phase-adj usting device also in circuit with the latter pressurecoil and the said portion of the autotransformer-winding, substantially as described.

5. In asystem of alternating-currentdistricurrent generator of current and pressure from said generator, the latter winding being divided into twocoils, an autotransformer bution, the combination with an alternating field-windings of a meter receiving current circuit with one of the pressure-coils, the coils of the pressure-windin g being inductively relatedya measuring device subjected to the ac-' tion of the field-windings, and a phase-adjusting device incircuit with theremaining pressure-coil and the secondary portion of the autotransformer-winding, substantially as de: scribed.

6. In a system of transmission, the combination with an-alternating-current generator of current and pressure field-windings of a meter receiving current from said generator the latter winding being divided into two inductively-related coils, an autotransformer having its winding included conductively in circuit with one ofthe pressure-coils and a portion of its winding included conductively in circuit with the remaining pressure-coil, an armature in inductive relation to the said pressure-coils, and a phase-adj usting device also in circuit with the latter pressure-coil and the said port-ion of the autotransformerwinding, substantially as described.

7. In a system of alternating-current distribution, the combination-with an alternatingcurrent generator of current andpress'ur'e field-windings of a meter receiving current from said generator, the latter windingbein'g divided into two coils, an autotransformer having its windinginoluded' conductively in circuit with one of the pressure-coils and a portion of its winding included conductively in circuit with the remaining pressure-coil,

a measuring device subjected to the action of thefield-windings, and a phase-adj usting device also inseries with the latter pressure-coil and the said portion of-the autotransformerwinding, substantiallyas described;

8., In a system of alternating=current distribution, the combinationwith analternating currentgenerator of current andpressure' field-windings of a meter receiving current from said generator, the latter winding being divided into two coils, an autotransformer having its winding included conductively in circuit with one of the pressure-coils, the coils of the pressure-windin g being inductively related, a measuring device subjected to the action of the field-windings, and a phase-adjusting device in series with the remaining pressure-coil and the secondary portion of the autotransformer-winding, substantially as described.

9. In a system of transmission, the combination with an alternating-current generator of current and pressure field-windings of a meter receiving current from said generator the latter winding being divided into two inductively-related coils, an autotransformer having its winding included conductively in circuit with one of the pressure-coils and a portion of its winding included conductively in circuit with the remaining pressure-coil, an armature in inductive relation to the said pressure-coils, and a phase-adjusting device also in series with the latter pressure-coil and the said portion of the autotransformer-winding, substantially as described.

10. In a system of alternating-current distribution, the combination with an alternating-currentgenerator of current and pressure field-windings of a meter receiving current from said generator, the latter winding being divided into two coils, an autotransformer having its winding included in series with one of the pressure-coils, and a portion of its winding included conductivelyin circuit with the remaining pressure-coil, and a measuring element, substantially as described.

11. In a system of alternating-current distribution, the combination with an alternating-current generator of current and pressure field-windings of a meter receiving current from said generator, the latter winding being divided into two coils, an autotransformer having its winding included in series with one of the pressure-coils, and a portion of its winding included in series with the second pressure-coil, and a measuring element, subjected to the action of the field-windings, substantially as described.

12. In a system of alternating-current distribution, the combination with the source of alternating current of two field-windings of a meter, one of said windings being divided into two coils, of an autotransformer having its winding included conductively in circuit with one of said coils and a portion of its windingincluded conductively in circuit with the other of said coils, and a measuring device subjected to the action of the field-windings, substantially as described.

13. In a system of alternating-current distribution, the combination with the source of alternating current of two field-windings of a meter, one of said windings being divided into two inductively-related coils, of an autotransformer having its winding included conductively in circuit with one of said coils and a portion of its Winding included conductivel y in circuit with the other of said coils, and a measuring device subjected to the action of the field-windings, substantially as described.

14. In a system of alternating-current distribution, the combination with the source of alternating current of two field-windings of a meter, one of said windings being divided into two inductively-related coils, of an autotransformer having its Winding included in series with one of said coils, and a portion of its winding included conductivelyin circuit with the other of said coils, and a measuring device subjected to the action of the field-windings, substantially as described.

15. In a system of alternating-current distribution, the combination with the source of alternating current of two field-windings of a meter, one of said windings being divided into two inductively-related coils, of an autotransformer having its winding included in series with one of said coils, and a portion of its winding included in series with the remaining coil, and a measuring device subjected to the action of the field-windings, substantially as described.

16. In a meter, the combination with current and pressure field-windings, the pressure field-winding being divided into two coils, of an impedance-winding in series with one of said coils, the remaining pressure field-coil being in a closed circuit with a metallicallycontinuous phase-modifying portion of the impedance-winding, substantially as described.

17. In a meter, the combination with current and pressure field-windings, the pressure field-winding being divided into two coils, of an impedance-winding in circuit with one of said coils, the remaining coil being in circuit with a metallically-continuons portion of the impedance-winding, substantially as described.

18. In aphase-modifying means, the combination with two fieldcoils, of an impedancewinding in circuit with one of said coils, a phase-modifying element being included between turns of the impedance-Winding, the remaining coil being included in a closed circuit with the said phase-modifying element, substantially as described.

19. In a meter, the combination with current and pressure field-windings, the pressure field-Winding being divided into two coils, of an impedance-winding in circuit with one of said coils, a phase-modifying element being included between turns of the impedance- Winding, the remaining coil being included in a closed circuit with the said phase-modifying element, substantially as described.

Signed by me at Fort Wayne, Allen county, State of Indiana, this 29th day of July, A. D. 1898.

. THOMAS DUNCAN.

WVitnesses:

M. G. WEBBER, CHARLES C. MILLER. 

